1. Field of the Invention
The present invention relates to a pixel structure and a repairing method thereof, and more particularly, to a pixel structure capable of being repaired easily and a repairing method thereof.
2. Description of Related Art
Thin film transistor liquid crystal displays (TFT-LCDs) having superior characteristics such as high definition, good space utilization, low power-consumption, and no radiation have become a mainstream product of displays. A common TFT-LCD is mainly constituted by a TFT array substrate, an opposite substrate, and a liquid crystal layer sandwiched between the opposite substrate. The TFT array substrate mainly includes a substrate, scan lines, data lines, and pixel structures arranged in an array on the substrate. The pixel structure is mainly constituted by a TFT, a pixel electrode, and a storage capacitor (Cst). Generally speaking, a scan signal transmitted by the scan line may turn on the corresponding TFT, and meanwhile, an image signal transmitted by the data line is transmitted to the corresponding pixel electrode through the TFT, such that the pixel electrode is able to control the liquid crystals there above, thereby achieving the purpose of display.
FIG. 1A is a schematic view of a conventional pixel structure, and FIGS. 1B and 1C are schematic cross-sectional views taken along a line a-b and a line c-d in FIG. 1A, respectively. Referring to FIGS. 1A and 1B, a conventional pixel structure 101 is disposed on a substrate 100 and is electrically connected with a scan line 102 and a data line 104. The pixel structure 101 includes a TFT 106, a common line 108, and a pixel electrode 110. The TFT 106 includes a gate 106a, a channel layer 106c, a source 106s, and a drain 106d. As shown in FIGS. 1A and 1B, the gate 106a of the TFT 106 is electrically connected with the scan line 102, the source 106s is electrically connected with the data line 104, the drain 106d is electrically connected with the pixel electrode 110 through the contact opening 112, thereby receiving the image signal transmitted by the data line 104. The common line 108 and the pixel electrode 110 form the storage capacitor Cst. FIG. 1C is a cross-sectional view of the storage capacitor. The common line 108 serves as a lower electrode of the storage capacitor Cst, and the pixel electrode 110 serves as an upper electrode of the storage capacitor Cst and is electrically insulated from the common line 108 through a dielectric layer 114 and a passivation layer 116, and thus the storage capacitor Cst enables the pixel structure 101 to maintain a good display quality.
In fabrication, the common line 108 of the pixel structure 101 is often open due to the particles or other factors, thereby causing abnormal display of the pixel, and generating defects on the LCD. In order to improve the grade of the display, the defects must be repaired. However, the conventional pixel structure 101 is not easy to be repaired, and thus the yield rate of the display cannot be effectively improved.